[Fixes #110009942] When cases are deleted, we pass through selectionDidChange where we must set _elementOrderIsValid to false so that updateSelection will actually do its work.
[Fixes #110009942] When cases are deleted, we pass through selectionDidChange where we must set _elementOrderIsValid to false so that updateSelection will actually do its work.

concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap,concord-consortium/codap